1. Field of the Invention
The present invenlion relates generally to elecrromagnetic wave shielded rooms and more specifically to an RF or radio shielded room which is also acoustically insulated.
2. Description of the Prior Art
RF or radio frequency shielded rooms are often found in laboratories to protect scientific instruments from stray electromagnetic radiation. They are also found in data processing centers to protect the integrity of data files from electromagnetic radiation. In addition, they are often used to prevent electronic evedropping. Representative examples of RF shielded rooms and the doors to seal such rooms are described in U.S. Pat. Nos. 4,370,831, 4,177,353, 3,518,355, 3,507,974, 3,256,384, 3,236,935, 3,009,984 and 2,757,225.
The above referenced patents generally describe RF shielded rooms that are fabricated from sheets of wood or particle board which are covered with metal. The RF shielded rooms also include special doors which seal the room. This type of RF shielding is usually attached to the frame of the existing room which is being shielded or requires framing to be built to support the RF panels. Accordingly, those RF panels are not inherently self-supporting.
In addition, known RF shielded rooms typically become less reliable in their shielding characteristics over time. They also are generally not fully demountable and reassemblable. That is, once known rooms are dissassembled they generally cannot be reassembled because in the assembly process known panels undergo some distortion which makes it virtually impossible to reassemble the panels without an attendant undesirable RF leakage.
There is also an additional problem in sealing the doors to these known shielded rooms because any crack or aperture between the door and the frame will degrade the quality of the RF shielding. Two approaches have generally been used to provide sealing of the doors. The first approach makes use of a door seal that has a groove with flexible metallic fingers. When the door is shut, a projection from the door is inserted into the metallic fingers, thereby sealing the gaps which would otherwise exist. The second approach includes inflatable conductive gaskets which seal the gaps between the door and its frame. Prior art door seals result in doors which often are not aesthetically pleasing. These doors are typically surface mounted, i.e., they are not flush with the wall, and they make it readily apparent that the room is being utilized for some special purpose.
In addition to the drawbacks mentioned above, known RF shielded rooms are not inherently soundproof. While prior art RF panels have some minimal sound insulating properties, these properties are quite small. Thus, in order to provide adequate acoustic insulation, conventional sound proofing techniques must be used within known RF shielded rooms. This results in a "room within a room" arrangement, i.e., the soundproof walls are built within the RF shielded walls or vice-versa. This arrangement is very time consuming and expensive. The contractor must install two sets of panels and must ensure that the installation of the acoustic insulation does not interfere with the RF shielding.
Accordingly, there is a need for a room which can provide both RF shielding and acoustic insulation and eliminate the necessity of building "a room within a room". There is also a need for such a room which retains its RF shielding and acoustic insulation characteristics over time and which are fully demountable and reassemblable. There is also a need for an aesthetically pleasing door for sealing such rooms.